Insert the ignition key and turn from position II (Ignition) to position 0 (All off) and back four times within three seconds.

Remove the ignition key. The locking control system is now in "learn mode" for the next 20 seconds and the red warning system LED stays on continuously to indicate this.

During the 20 seconds press one of the transmitter buttons. The remotes signal and code number is learned by the locking module and is indicated by flashing the warning system LED.

Wait until learn mode times out (20 seconds) or switch the ignition back to ON.

If it is a keyfree system it's more awkward as you have to use the manual key blade, I'm not totally sure of the routine, Someone else here may be able to advise better on that or a trip to Ford may be needed.

If you do need another key, they are available on eBay, you would just need to swap the circuit board over and programme as above, your immobiliser transponder chip (carbon chip) will be ok and making sure you keep your original chip will save you a lot of trouble (and money).